1. Place a large skillet over medium heat.
2. Add the beef being sure to break up with a fork.
3. Stir in the onion and garlic.
4. Cook on medium heat until the meat is cooked completely through.
5. Drain off excess grease.
6. Preheat the oven to 350 degrees.
7. Prepare a large baking dish with a non stick cooking spray.
8. Spread the meat mixture into the baking dish.
9. Spread the potatoes over the top.
10. Spread the carrots over the potatoes.
11. Sprinkle the corn on top.
12. Add the diced peppers as the last layer.
13. Mix together the soup and milk in a large bowl until smooth.
14. Pour the soup over the casserole.
15. Sprinkle the Parmesan cheese over the top of the entire casserole.
16. Place aluminum foil tightly over the top of the dish.
17. Bake 45 minutes or until heated through.